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-Structure paper
タイトル | Structural basis of chiral wrap and T-segment capture by DNA gyrase. |
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ジャーナル・号・ページ | Proc Natl Acad Sci U S A, Vol. 121, Issue 49, Page e2407398121, Year 2024 |
掲載日 | 2024年12月3日 |
![]() | Elizabeth Michalczyk / Zuzanna Pakosz-Stępień / Jonathon D Liston / Olivia Gittins / Marta Pabis / Jonathan G Heddle / Dmitry Ghilarov / ![]() ![]() |
PubMed 要旨 | Type II topoisomerase DNA gyrase transduces the energy of ATP hydrolysis into the negative supercoiling of DNA. The postulated catalytic mechanism involves stabilization of a chiral DNA loop followed ...Type II topoisomerase DNA gyrase transduces the energy of ATP hydrolysis into the negative supercoiling of DNA. The postulated catalytic mechanism involves stabilization of a chiral DNA loop followed by the passage of the T-segment through the temporarily cleaved G-segment resulting in sign inversion. The molecular basis for this is poorly understood as the chiral loop has never been directly observed. We have obtained high-resolution cryoEM structures of gyrase with chirally wrapped 217 bp DNA with and without the fluoroquinolone moxifloxacin (MFX). Each structure constrains a positively supercoiled figure-of-eight DNA loop stabilized by a GyrA β-pinwheel domain which has the structure of a flat disc. By comparing the catalytic site of the native drug-free and MFX-bound gyrase structures both of which contain a single metal ion, we demonstrate that the enzyme is observed in a native precatalytic state. Our data imply that T-segment trapping is not dependent on the dimerization of the ATPase domains which appears to only be possible after strand passage has taken place. |
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手法 | EM (単粒子) |
解像度 | 2.6 Å |
構造データ | EMDB-51339, PDB-9ggq: |
化合物 | ![]() ChemComp-MG: ![]() ChemComp-MFX: ![]() ChemComp-HOH: |
由来 |
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![]() | ISOMERASE / DNA gyrase / type II topoisomerase / moxifloxacin / DNA crossover |